As known, there are numerous types of fittings for a wide variety of uses. In particular, fittings for high-pressure pipes suitable for use on industrial construction machines, such as earth-moving machines or lifting machines and the like, must be able to be assembled easily, also on a building site, and ensure an excellent seal together with good strength and long life.
Normally, the known fittings have a nut suitable for hydraulic connection with a connection element, which can be a pipe union or similar that is held at the end of the high-pressure pipe through an additional element, which can be a ring fixed integrally to the end of the pipe. Retention of the ring to the pipe is made essentially by bending the end of the pipe by about 90° so as to form a small collar, obtained by squashing of the material, which prevents the ring from slipping off the pipe and consequently also from the nut.
This technical solution, for example, has the drawback that the small collar that is not as thick as the walls of the pipe, forming a weak point thereof. Moreover, the ring must be slotted onto the pipe at a specific spacing from its end to be bent, making such an operation complex. Moreover, the ring must also be held radially by the pipe, otherwise it tends to slip off both due to the operating pressure and when the nut is tightened. Last but not least, the particular squashing processing by dragging of the small collar means that its front surface has an uncontrolled degree of roughness that could compromise the seal with the gasket with which it is associated.